Interconnection of electrical lines



June 16, 1925.- v 1,542,361

I a s. A. BETUJLANDER j lurincouuncrlou OF ELECTRICAL LINES '7 Filed Aug.-11. 1922 2 Sheets-Sheet 1 TQIKI June 16, 1925.

G. A. BETULANDER INTBRCONNBCTION OF ELECTRICAL LINES Aug. 11. 1 1922 2 Sheets-Sheet 2 Patented June 16, 1925.

UNITED STATES 1,542,361 PATENT OFFICE.

GOTTHILF ANSGARIUS BETULANDER, OF SODER'I'ORNS VILLASTAD, SWEDEN, AS-

SIGNOR TO THE RELAY AUTOMATIC TELEPHONE COMPANY, LIMITED, OF LONDON,

ENGLAND.

INTEROONNEGTION OF ELECTRICAL LINES. I

To all whom it may concern:

Be it known that I, GOTTHILF ANsGARIUs BE'IULANDER, a subject of the King of Sweden, and resident of Sodertorns Villastad, Sweden, have invented a new and useful Improvement in the Interconnection of Electrical-Lines, of which the following is a specification.

The invention relates to relay switches for interconnecting electrical lines, particularly subscribers lines and junction lines in telephone plants.

The object of this invention is to provide switching apparatus which shall be simpler in operation than those hitherto proposed and more flexible, that is, more readily adapted to changing conditions of trafiic.

The invention is illustrated by the accompanying drawings, in which Figure 1 shows the general scheme of a known arrangement, Figure 2 is a diagram illustrating that arrangement, Figure 3 is a diagram showing the arrangement according to the present invention in which each of certain outgoing lines is connected to all the sets of contacts of the switch, While Figure 4 shows a modific-ation of the arrangement according to the present invention in which more than one outgoing line isconnected to each set of contacts. V

Figure 5 shows the circuit for the arrangement shown in Figure 3. Figure 6 shows a modification of the arrangement shown in Figure 5.

Figure l of the accompanying drawings shows the general scheme of a known switching arrangement for interconnecting lines by means of relays. In such schemes it is generally required that connections may be established between two groups of lines G and G in such a manner that each line AL of one group may have access to any line FL of the other group. It may be assumed as an example that group G comprises 100 subscribers lines and that group G comprises, for instance, 10 junction lines in an automatic telephone exchange. The small circles at the'crossing points of the difi'erent lines then represent the means by which the lines are connected together. When using simple relays for effecting the connections, either one relay may be provided at each connecting point, the number of relays being then-equal to the product of the numbers of the lines in each group, or relay switches different combinations in made up of a smaller number of operative w nd ngs may be used in which case the windings are arranged to be energized in a known manner, each connection being eifected by the combined action of, for instance, two windings. A switch of the kind last mentioned is schematically illustrated in Figure 2. For practical reasons the contacts for interconnecting the lines must be arranged on'a plurality of such switches, so that in an arran ement according to Figure 1 the subscribers lines are divided in ten sub-groups UG UG UG each including ten lines and one switch being assigned to each subroup. Ten switches are therefore required or effecting all connections. The sets of contacts KG enclosed by chain lines in Figure 1 will then belong to different switches of the kind shown in Figure 2. i

In Figure 2 the lines AL and FL are drawn in chain lines. Each set of contacts is represented by two contact springs, the lower of which is adapted to bee erated by a corresponding arm a-extending mm a rod A pivotally mounted along the corresponding horizontal row. The arms a are normally inoperative and may be caused to actuate the corresponding sets of contacts by means of arms m extending from vertical,

pivotally mounted rods M. The rods M and A are provided at their ends with arma tures adapted to be operated by electromagnets MR and AR, the rods being thereby turned in the direction of the arrows. The selection and o eration of the different sets of contacts is effected by energizing the magnets MR and AR in different combinations in the following manner. If, for instance, the contact KG is to be operated, the magnets MR and AR will be energized, the magnet MR being first caused to operate and then magnet AR Rod M is thereby turned so as to bring its arms m into operative position beneath the different sets of contacts of the corresponding vertical row, and the arms a; of the appertaining rod A are then turned upwards. The arm a; corresponding to the contact set KG then actuates the corresponding arm m of the rod M so that the lower contact spring is brought into contact with the upper contact spring. Thus connectionis established be tween lines AL and FL Immediately after the connection has been effected magnet MR is deenergized whereupon rod M is returned to its normal position by the action of a spring and consequently all arms on. are returned except that one beneath the contact set KG, which arm is retained in operative position by the action of arm a. This is rendered possible by arms on. bemg either pivotally connected to rod M or made of elastic wires or the like. Disconnection is effected by deenergizing magnet AR, arm m then resumin its normal position. If lines AL and F 2 are to be connected together this is eifected in a similar manner by energizin magnets MR and AR It will be seen f rom the above that by the operation of two members A and M crossing each other, only the set of contacts located at the crossing point of the corresponding horizontal and vertical rows will be operated.

The present invention contemplates the use of relay switches of the kinds described in a new manner in respect of the connection of the switches to the lines to be connected. The invention is schematically illustrated in Figure 3 in which the lines and the switches are shown in a manner analogous to Figure l.

In relay switching systems as hitherto carried out, for instance, the system shown in Figure 1, there are in each switch as many incoming and outgoing lines as there are vertical and horizontal rows of contact sets respectively, each line having consequently only one row of contact sets in each switch. According to the present invention, however, the sets of contacts pertaining to each line of one line group (incoming or outgoing lines), are distributed over a plurality or, if wanted, over all rows of contacts of the switch. Figure 3 shows the arrangement when each outgoing line FL is connected to all sets of contacts of the switch, there being then as many switches as there are lines in the group Gr of outgoing lines. This alteration of the connection of the switches has for its object partly to simplify the switching apparatus and circuits controlling the switching operation, partly to make the lines more independent of one another so as to facilitate the shifting of the switches from one line group to another according to the variations of the trafiic for the purpose of better utilizing the switches. It has the additional advantage when used with switches, such as are shown in Figure 2, in which the contact groups are rigidly mounted, that the number of trunks can be varied readily.

In the arrangement shown in Figure 1 to decrease the number of trunks would leave contacts unused, and to increase the number of trunks would require structural alteration of the switches.

In the arrangement shown in Figure 3 variation in the number of trunks can be effected by increasing the number of switches.

If wanted two or more of the switches shown in Figure 3 may be built together into one switch with common operating mechanism. Figure 4 shows such an arrangement in which the sets of contacts pertaining to two outgoing lines are brought together in a single multiple, the number of switches being then half the number required in Figure 3,v whereas the capacity of each switch will be twice as large.

It should be observed that the invention is not limited to the use of switches of the particular construction shown in Figure 2. It is only essential that the sets of contacts should be arranged in intersecting rows and that the members for selecting and operating the sets of contacts should be arranged along these rows in such a manner that by operating two intersecting members only the set of contacts located at the point of intersection of the corresponding rows will be operated. Otherwise the construction of the operating mechanism may be modified in many ways, for instance, by arranging each rod M in common to several vertical rows, the rod being then adapted to be set into one of several positions.

Figure 5 shows the circuits for an arrangement according to Figure 3. Two outgoing junction lines FL and FL and appertainin switches RV and RV are represented. 6nly such parts of the switches are shown as are required for establishing connections with four subscribers lines AL connected to two vertical rows of the switches. The circuits of the marking and connecting relays MR and AR of all switches are controlled by a common switching device comprising a searcher RS, switching relays OR and auxiliary relays SR and TR. The circuits of the marking and connecting relays are also carried over contacts of group relays GR GR assigned to the different switches, the arrangement being such that the marking and connecting relays of each switch can only be operated when the corresponding group relay GR is energised. The operation is as followss- Upon a call occurring, for instance, on subscribers line AL, a circuit 1 is closed over the subscribers line and through its line relay LR. The latter energizes and closes a circuit 2 through the first relay PR of the searcher RS and over contacts is of the connecting relays of the first, switch, provided the first junction line FL is disengaged at the time.

If this line should be engaged, one of the appertaining connecting relays AR will be energized and the corresponding contact is be open, circuit 2 being then closed through the second relay PR of the searcher (provided the second junction line F L is dis engaged), or through some other relay PR not shown in the drawing, which corresponds to a disengaged junction line FL.

Upon relay PR energizin a circuit 3 is closed through group relay R which operates and connects itself into a holding circuit over its contact is, Relay GrR also closes circuit 4 through switching relay OR which cuts into circuit relay R When relay 0R energizes the searcher is shifted at the contacts is from the test wires PL of the injunction lines to lines RL which serve to mark the presence of calls on lines pertaining to the different sets of vertical rowsof the switches, by the said lines RL bein connected to earth over contacts on the line relays LR. As the calling subscribers line is connected in this instance to the first Vertical rows, a circuit 5 is completed-through the relay PR of searcher RS said relay now closing circuit 6 through marking relay MR pertainin to the first vertical row. The latter re ay energizes and receives holding current over circuit 7 which includes switching relay OR. OR operates and immediately cuts in relay OR. By the operation of relay OR searcher BS is shifted at contact In to lines SL which serve to mark (by the closure of contacts of the line relays LR) the presence of calls among the lines connected to a separate vertical row of contacts. Suppose line AL to be the only calling line of those connected to the same vertical row, circuit 8 will be completed through relay PR of the searcher. This relay will now close cir-' cuit 9 through one winding AL of the first connecting relay AR and through relay SR. Relay AR energizes to establish connection between subscribers line AL and junction line FL through contact set KG At the same time by the connection of the subscribers line to relay FR in the 'unction line circuit 10 was closed throug relay FR. This relay in turn closes holding circuit 11 for connecting relay AR throng the winding HL of this relay and through the subscribers cut-ofi' relay UB The latter cuts off line relay LE in the usual way.

The circuit which operated connecting relay AR initiated the disconnection of the common switching device by relay SR closing circuit 12 for slow release relay TR which cuts in slow release rela TR The latter opens the holding circuit for group relay GR which then de-energizes and cuts oil relay MR relays 0B and relay SR. The common switching device is thus prepared for effecting another call.

If two calls should occur simultaneously on lines pertaining to different vertical rows, circuit 5 will at first be branched through both relays PR. and PR of the searcher. As the first relay PR opens at once the circuit of the second relay PR it is evident that only the calling line of the first vertical row will obtain connection, whereas the other calling line has to wait .till the first connection has been elfected.

If two calls occur simultaneously among the common searcher IRS has for its objectpartly to select a disengaged junction line and partly toprevent double connections when several calls occur simultaneously. Figure 6. shows a modification of the arrangement of Figure 5, in which these operations are efl'ected by the marking relays of the relay switches and by the line relays of the subscribers lines whereby the common searcher may be dispensed with. The selection of a disengaged junction line by means of the marking relays'ltLR is rendered possible accordin to the arran ement shown in Figure 6 by these relays being directly inserted in the test circuits of the corresponding junction lines, which circuits include the breaking contacts is, [0 etc., of the connecting relays, and by the marking relays mutually controlling their circuits in a similar manner to that in which relays PR control each others circuits.

Upon a call on the line AL, for instance,

line relay LR is operated as before and (supposing the first jutnction line to be disengaged) circuit 13-is completed through the appertaining marking relay MR of they first relay switch and through a relay RR common to the whole group of subscribers. If at this moment also the second junction line is disengaged, a short current impulse is simultaneously obtained through marking relay MB of the second relay switch, said impulse, however, being immediately interrupted at contact k upon relay MR of the first relay switch energizing. It will consequently have no influence on the switching operation. The first relay MR closes circuit 14 through one winding of connecting relay AR which is at once connected into holding circuit 15. At the same time also the connecting relays AR of the other relay switches are operated (prov-id ed said relays have not been previously energized). As, however, at the time no marking relay is operated in the other switches, no connection is eflected in these switches. hen the marking relay of the first switch energizes and the calling line shall have become connected to relay F R a holding circuit 16 is closed over the third wire and through the subscribers cut-01f relay UR which cuts off line relay LR. At the same time circuit 13 for relay RR and marking relay MR is opened at contact 70 of AR and as a consequence the temporary holding circuits 15 of all connecting relays AR are opened. After that only the connecting relay AR of the first switch is maintained in operative position. The switching devices are now againready for effectin another connection.

If calls should occur simultaneously on lines AL and AL line AL will first be connected owing to the corresponding line relay LR opening the circuit of connecting relay AR at its contact k simultaneously with the closing of circuit 14: of connecting relay ARK Similarly relay LE opens the circuit of the next connecting relay and so on. Thus when several calls occur simultaneously in the same sub-group UG, only one connecting relay AR will be operated at a time and double connections are therefore prevented.

The same result is obviously attained it the line relays LR of eachsub-group UG mutually control their circuits in a manner analogous to the control of the circuits of the relays PR of the searcher RS, Figure 5.

If calls occur simultaneously on the lines AL and AL, that is, on lines pertaining to two difl'erent sub-groups UGr and UG or two different vertical rows of the switches, only marking relay hlR pertaining to subgroup UG will operate owing to the relay last mentioned opening the circuit of relay MR at its contact k Similarly the circuit of marking relay MR would be carried over a back contact of the next marking relay and so on, the marking relays thus mu tually controlling each others circuits in the same way as the relays PR of the searcher RS, Figure 5. When calls occur simultaneously in several sub-groups or vertical rows the calls will therefore be efiected successively in the order in which the corresponding marking relays are connected, so that in this case also double connections are prevented.

What 'I claim is v 1. The combination of a plurality of lines of one order, a plurality of lines of a second order, a plurality of sets of contacts, the contacts ofeach set being arranged in intersecting rows and columns, each line of the second order being connected to only one set of contacts but to more than one row of contacts in that set and each line of the first order being connected to as many contacts in each of the sets as there are lines:"of the second order connected to that set, a relay adapted to control each row of each set and a relay adapted to control each column of each set.

2. The combination of a plurality of lines of one order, a plurality of lines of a second order,'a separate set of contacts connected to each line of the second order, the contacts of each set being arranged in intersecting rows and columns, each line of the first order being connected to only one contact of each set, a relay adapted to control each row of each set and a relay adapted to control each column of each set.

3. The combination of a plurality of lines of one order, a plurality of lines of a second order, a number of sets of contacts, the contacts of each set being arranged in intersecting rows and columns, each line of the second order being connected to only one set and each line of the first order being connected to as many contacts of one column of each of the sets as there are lines of the second order connected to that set, a relay adapted to control each row of each set and a relay adapted to control each column of each set.

4. The combination of a plurality of lines of one order, a plurality of lines of a second order, a plurality of sets of contacts, the contacts of each set being arranged ,in intersecting rows and columns, each line of the second order being connected to only one set of contacts and each line of the first order being connected to as many contacts of each of the sets as there are lines of the second order connected to that set, a relay adapted to control each row of each set, a relay adapted to control each column of each set, a line relay associated with each line of the first order, and means whereby the line relays control the circuits of the relays controlling the various rows of the various sets.

- 5. The combination of a plurality of lines of one order, a plurality of lines of a second order, a separate set of contacts connected to each line of the second order, the contacts in each set being arranged in intersecting rows and columns, each line of the first order being connected to only one contact of each set, a relay adapted to control each row of each set, a relay adapted to control each column of each set, and means whereby only one of the last mentioned relays can operate or remain in operative position at any instant.

6. The combination of a plurality of lines of one order, a plurality of lines of a second order, each line of the second order comprising three wires, a plurality of sets of contacts, the contacts of each set being arran ed in intersecting rows and columns, each ine of the second order being connected to only one set of contacts and each line of the first order being connected to as many contacts of each of the sets as there are lines of the second order connected to that set, a relay adapted to control each row of each set and a relay adapted to control each column of each set, the last mentioned relays being inserted in the third wires of the lines of the second order.

7. The combination of a plurality of lines of one order, a plurality of lines of a second order, each of the lines of the second order comprising three wires, 3. separate set of contacts connected to each line of the second order, the contacts of each set being arranged in intersecting rows and columns,

each line of the first order being connected to only one contact of each set, a relay adapted to control each row of each set and a relay adapted to control each column of each set, the last mentioned relays being inserted in the third Wires of the lines of the second order.

In testimony that I claim the foregoing as my invention I have signed my name this 18th day of July 1922.

GOTTHILF ANSGARI'US BETULANDER. 

